1. Field of the Invention
The invention relates to an integrated process for producing hydrogen rich gas in a reformer furnace, reformer furnaces and furnace structure. More specifically, the invention relates to a reformer furnace operating under pressure on both the process and heat side. The invention has particular application for producing hydrogen rich gas for commercial size coal gasification plants.
2. Description of the Prior Art
Recently, considerable interest has been generated in producing gas for energy requirements by coal gasification. Certain commercial size coal gasification plants demand large quantities of hydrogen rich gas. Hydrogen rich gas is also currently used on a large scale in the commercial synthesis of ammonia.
Large amounts of gaseous hydrogen and carbon monoxide mixtures, commonly referred to as synthesis gas, are currently required for use in commercial size plants producing methanol from natural gas or light hydrocarbons.
The hydrogen rich gas and synthesis gas required for commercial applications are produced by reformer furnaces. The commercial reforming process is carried out in a reformer furnace wherein a stream of hydrocarbon and steam is passed through the furnace tubes which are filled with catalyst, such as nickel oxide. The reforming reaction is commonly carried out in the temperature range of 1000.degree. to 1500.degree.F. or lower.
The conventional hydrocarbon reforming furnace is a radiant type furnace wherein the heat source is derived from the combustion of a hydrocarbon fuel and air at atmospheric pressure. The present state of the art radiant type reformer furnaces are very large and expensive and require considerable fuel.
Furnaces which operate under pressure also exist. One such furnace is disclosed in U.S. Pat. No. 3,582,296 (June 1, 1971). Basically, the furnace therein is designed to operate with the pressure difference between the process stream and the high-temperature heating gas as small as possible. The furnace is designed to provide heating essentially by radiation and rely on bringing the combustion gas in the heating zone as close as possible to the theoretical combustion flame temperature. Another furnace designed to operate under pressure is the compact convective reactor shown in U.S. Pat. No. 3,688,494 (Sept. 5, 1972).